CONVERGENT EVOLUTION 249 



examples of convergent evolution within much narrower limits. 

 They can only be regarded as homologous to the extent of all being 



FIG. 104. Skeleton of the Giraffe, showing the seven separate and greatly 

 elongated cervical Vertebra. (From Brehm's "Thierleben.") 



pentadactyl. They do not owe their special characters as wings 

 to descent from a common ancestral winged form, but have been 



